The present invention relates generally to agricultural round balers which form cylindrical bales using one or more movable belts and/or rollers disposed in a bale-forming chamber and, more particularly to an improved system for guiding the movable belts around fixed rolls to improve belt tracking.
Round balers have become quite prevalent for their capability of producing a conveniently sized cylindrical bale, very often automatically wrapped with a sheeting material such as net or film. Crop material, such as hay, is picked up from the ground as the baler travels across the field, and is fed into an expandable chamber where it is rolled up to form a compact cylindrical hay package.
Prior art round balers generally have an expandable bale chamber defined by a pair of fixed sidewalls, and a plurality of side-by-side belts cooperating with a series of transverse rolls mounted between the fixed sidewalls. Some guide rolls are fixed in position while others may be mounted on moveable apparatus such as a moveable tailgate to control the belts during tailgate opening and closing. The chamber includes an inlet opening in the front through which crop material is fed. Also included is a pair of take up arms pivotally mounted on the main frame, between which arms multiple of guide rolls are journalled. A biasing force is applied on the take up arms to urge the outer surfaces of the guide rolls against the belts to maintain belt tension and prevent slack from occurring in the belts during expansion and contraction of the chamber.
Guide rolls traditionally comprise an elongate, rotating cylinder spanning the width of the bale chamber between the side walls around which all of the belts comprising the bale forming chamber are directed. Variations in length among the individual belts causes belt slippage as all belts engage the guide roller at a uniform peripheral speed across the roller width. Belt slippage causes increases friction and wear on the belts. It may also lead to belts wandering laterally across the rollers and deviating from their straight line tracking. The result is increased wear on the belts, potential damage to the belts, and diminished baler performance. In the extreme, excessive friction and the resultant heat poses a risk of fire in the baler. The traditional method of maintaining proper belt tracking involves incorporating fixed guides along which the edges of the moving belts slide as they are rotated around the bale chamber. Friction between the moving belt edges and the fixed guides still result in increased belt wear and reduced belt service life.
It would be desirable to provide an improved belt roller system for a round baler that would improve individual belt tracking in the baler and alleviate the problems with known belt tracking solutions.